Many remote controls for entertainment devices include a feature that detects a low battery condition and alerts the user of the low battery condition. For example, a remote control for a satellite television receiver may detect that the battery powering the remote control only has 10% of its usable life left. The remote control may communicate the low battery condition to the satellite television receiver, and the receiver may present an indicator to a user regarding the low battery condition. Thus, the user may take action to replace the batteries to avoid experiencing a subsequent dead battery in the remote control.
The low battery conditions typically detected based on comparing a terminal voltage of the battery with a low battery threshold voltage. The usable life of the battery is directly correlated with a terminal voltage of the battery. A specified point on a voltage discharge curve indicates a remaining usable life of the battery. However, there are many different types of batteries, and each type of battery does not follow the same voltage discharge curve. For example, a terminal voltage of ˜1.20 V may correspond to 10% of the remaining usable life of a nickel metal hydride (NiMH) battery, whereas a terminal voltage of ˜1.05 V may correspond with the same remaining usable life of an alkaline battery. Because the batteries of a remote control may be replaced with either type of battery, the utilization of a single threshold value indicating a low battery condition often results in providing a user with little warning regarding dead batteries or prompting the user to replace the batteries more often than necessary. Thus, the user may become dissatisfied with the battery replacement indicators provided by the satellite television receiver.